Q:

Problem PageA textbook store sold a combined total 217 of history and chemistry textbooks in a week. The number of chemistry textbooks sold was 57 less than the number of history textbooks sold. How many textbooks of each type were sold?

Accepted Solution

A:
Answer: 137 history books were sold80 chemistry books were soldStep-by-step explanation:Let x = the number history textbooks sold by the textbook store in that week.Let y = the number chemistry textbooks sold by the textbook store in that week.The textbook store sold a combined total 217 of history and chemistry textbooks in the week. This means x + y = 217 - - - - - -1The number of chemistry textbooks sold was 57 less than the number of history textbooks sold. This meansx = 57 + ySubstituting x = 57+ y into equation 1. It becomes57+y+y= 21757 + 2y = 2172y = 217 - 57 = 160y = 160/2 = 80x = 57 + y = 57 + 80x = 137137 history books were sold80 chemistry books were sold